1. Technical
This invention relates generally to a method and apparatus for separating valuable material from unwanted material in a mixture, such as a pulp slurry.
2. Description of Related Art
By way of example, in many industrial processes flotation may be used to separate valuable material from unwanted material. In this process a mixture of water, valuable material, unwanted material, chemicals and air is placed into a flotation cell. The chemicals are used to make the desired material hydrophobic, and the air is used to carry the material to the surface of the flotation cell. When the hydrophobic material and the air bubbles collide, they become attached to each other. The bubble rises to the surface carrying the material with it.
The performance of the flotation cell is dependent on the bubble surface area flux in the collection zone of the cell. The bubble surface area flux is dependent on the size of the bubbles and the air injection rate. Controlling the bubble surface area flux has traditionally been very difficult. This is a multivariable control problem, and there are no dependable real time feedback mechanisms to use for control.
The mineral recovery of such a process can be highly dependent on the mineral particle size distribution entering the flotation cell. Typically, coarse and fine particles recovery can be significantly less than the optimal particle size. Mining operations routinely discharge large well liberated particles to the tailings pond.
In contrast to the aforementioned flotation process using air bubbles, the assignee of the present invention has designed an alternative machine and process for recovering valuable minerals from mineral rich pulp slurry, e.g., consistent with that set forth in the aforementioned family of applications. This mineral rich pulp slurry could be any type of slurry being air conveyed ground minerals or an aqueous mixture for example. This mineral rich slurry is put into contact with a functionalized polymer surface which has been engineered to attract the mineral of interest. The surface could be anything from an engineered bubble to a flat plate. After the functionalized polymer surface attaches to the mineral of interest, the unwanted material is washed away and only the desirable mineral is left on the functionalized polymer surface. The enriched surface is then treated so that the mineral is released and collected. The functionalized polymer surface can then be reused.